Gas burner



Nov. 21, 1944. H. L. BROWNBACK GAS BURNER Filed Dec. 26, 1939 2Sheets-Sheet 1 Nov. 21, 1944. H. L. BRowNBAcK GAS BURNER 2 Sheets-Sheet2 Patentecl Nov. 21, 1944 UNITED STATES PATENT OFFICE GAS BURNER HenryLowe Brownback, Norristown, Pa. Application December 26, 1939, SerialNo. 310,995 15 Claims. (Cl. 158-99) This invention is a novelimprovement in gas burners, particularly adapted for use in cookingkettles, or by air currents if the gas is turned low, and such burnerscannot be. used for broiling in.

the usual manner of placing the food to be broiled above the burner.Furthermore the heating-surface of such burners is not uniform, but islocalized along the axes of the series of burner orifices.

The principal objects of my invention are to provide an improved subsurface combustion type burner designed to eliminate all of the abovementioned disadvantages and to provide a burner which will present aneven fire resembling in heat distribution and appearance a fine charcoalfire, above which food can be broiled without absorbing any gas" taste;also to provide a burner in which the gas is burned into carbon dioxideby reason of multiple combustion steps, thus producing maximum heat froma given quantity of gas; also to provide a burner which willbe lesssubject to maladjustment than the ordinary burner, and in whichprovision is made to render same safe against overflowing pots andkettles; also to provide a burner in which there are no small burnerorifices exposed to dirt, grease and corrosion as in the ordinary typeburner, and hence to provide a burner in which there is no danger ofclogging or choking the jet orifices.

I will explain the invention with reference to the accompanyingdrawings, which illustrate several practical embodiments thereof toenable others familiar with the art to'adopt and use the same; and willsummarize in the claims the novel features of construction, and novelcombinations of parts, for which protection is desired.

' In said drawings:

Fig. 1 is a vertical section through one form of my novel gas burner.Fig. 2 is a vertical section showing a modification'utilizing apre-formed filter cartridge unit in the secondary mixing chamber of theburner. Fig. 3 is a vertical section through a further modificationshowing one form of cover used on the secondary mixing chamber. Fig. 4is a'vertical section showing another form of cover for the secondarymixing chamber.

My novel gas burner preferably comprises a cup-shaped casing I, open atthetop and having a bottom plate Ia. provided with a contractedextension lb, the lower end of which is provided with a downwardlyflaring hood lo, the parts lb and le forming the primary gas and airmixing chamber M' of. the burner. Extending upwardly into hood Ic is agas nozzle 2 having an orifice 2a governed by amanually adjustable valve3 to control the amount of gas entering from the gas pipe 2b into theprimary mixing chamber M. Air enters the primary mixing chamber M at thelower open end of hood ic exteriorly of the nozzle 2, and preferably airregulating means is provided consisting of a pair of relativelyadjustable superimposed perforated plates Id at the lower end of thehood Ic. If desired an air blower 6r other means for supplying forceddraft of air intothe primary mixing chamber M may be provided.

Within the casing I and spaced from the lower end thereof is a. screenor grating 4 preferably extending across the casing and supported on anannular frame 4a fitted Within the walls of the casing. The chamberbelow the screen or grating 4 may be empty to provide a secondary mixingchamber M2'for the gas and air; or if desired said space below screen 4may be filled with tinsel or the like to assist in mixing thegas and airtherein. Above the screen or grate 4, the

casing I is packed with non-combustible porous packing material P (inFig. 1) such as asbestos, rock wool, spun glass, or the like, forming agas distributor and backfire trap. The upper face of packing P forms thebottom of the primary combustion chamber C, which chamber is formed in acasting '5 having a contracted lower end 5a into which the upper end ofcasing l enters, leaving a space 51) between the parts 50. and i throughwhich the secondary air for the primary combuse tionchamber C enters.

Within the lower portion of casing 5 is a refractory lining 6 ofsubstantial thickness to protect the walls of the casing and to preventloss of heat therethrough. Lining 5 extends substantially half theheight of casing 5: Seated in an annular recess at the top of the lining6 is a grate I above which is disposed a screen 8. Above screen 8 is arefractory lining 6b extending to the top of the casing 5. Upon screen 8is a layer,9 of carber C2. The bed, of aggregates above the screen 8 inthe chamber provides for secondary combustion and heat distribution, theaggregates becoming incandescent by action of the combustion in theprimary combustion chamber C, and the secondary combustion in the layer9 maintains a. glowing bed of aggregates in chamber 5 giving a radiantheat with practically no flame.

For the purposeof igniting the air and gas mixture in the primarycombustion chamber C, I provide a pilot consisting of a gas tube Inentering the side of easing 5 and extending through lining 6, said tubehaving a jet orifice Illa at its inner end for the pilot flame which maybe left burning at all times. The pilot flame provides double safety asany possible escape of gas due to a partially closed cock in gas pipe 2bwould not pass directly into the air as in the ordinary burner but wouldcollect in the primary combustion chamber C and would there be ignitedby the pilot light IOa; and since the pilot Illa is disposed in theenclosed combustion chamber C there would be little likelihood of thepilot flame being extinguished by a sudden gust of wind. Above the pilotorifice Illa is a deflector plate Illb for the purpose of preventing anyliquids which might drip .down into the primary-combustion chamber Cfrom extinguishing the pilot flame.

Instead of using the filling P in the casing I as shown in Fig. 1, thefilling can be made up as a cartridge shown in Fig. 2, similarly to theoilfilter cartridges used in motor cars, and this cartridge replacedperiodically if found necessary or desirable. The pre-formed burnercartridge as shown consists of a metallic shell II of diameter and sizeto suit the internal dimensions of the casing I, said shell preferablyhaving internal annular flanges I Ia at its ends. Within the shell II isa shell I2 of less height seated upon the lower flange Ila, and upon thetop of shell I2 is a screen or grid I3 forming the top of the secondarymixing chamber M2. Above the screen or grid I3 is a packing of porousinsulating material such as rock wool, asbestos, spun glass, or thelike, and upon the top thereof is a screen or grid I5a upon which is alayer of asbestos fibre or the like I5 covered by a screen IGengagingthe upper flange I la of the shell I I. The above construction forms aunit-which may be inserted as a cartridge intothe. casing I, which unitis inexpensive to manufacture and is readily removable from andreplaceable in the casing. The cartridge shown in Fig. 2 also providesan eflicient backfire trap, and the gases passing up through the porouslayers I4 and I5 are spread evenly throughout the mass ,so that theflame at the top of .layer l6 will burn evenly over the entire area ofthe casing I whichforms the bottom of the primary combustion chamber C.

It may be found desirable to provide covers upon the casing I such asshown in Figs, 3 and 4, as an added safety measure to protect thecartridge from any liquids which might .boil over and pass down throughthe combustion chambers C2 and C and which might thus soak the cartridgeor injure same. The cover may consist of an overlapping series ofconical rings '20 with spacers between adjacent rings as shown in Fig.3; or the cover may consist of a conical plate 2| having louvres 22formed therein as shown in Fig. 4, or may be otherwise formed to deflectany liquid which might drop through the combustion chambers from fallingon the cartridge. In case a large volume of liquid was spilled on theheated layer 9 of non-combustible material suflicient to cool the latterand pass down through on the burner, such liquid would run down theconical covers and pass out of the secondary air inlets 5b withoutextinguishing the burner. Preferably 5 the cover is provided with aflange adapted to flt within the upper end of the casing I. When a coveris used the porous filling material P in the casing would preferablyextend up to the underside thereof, and the porous insulating material.10 P would distribute the gas-air mixture evenly to the underside .ofthe protective cover and the mixture would pass through the slots. orlouvres and burn,

The operation'of the burner as described is as 15 follows: In my novelburner the gas and air is fed into a primary mixing chamber M in theusual manner either by the injector action of a Bunsentype mixer. or bya forced draft blower type mixer, and the gas-air mixture is carried tothe secondary mixing chamber M2 which is open at the top and may beempty or filled with tinsel or like material through which the mixturecan circulate freely. The gas-air mixture then passes upwardly throughgrid or screen 4 or I3 into a bed of porous insulation P or l4-I5 in thecasing I which distributes the gas-air mixture evenly at the uppersurface thereof, at which point the gas-air mixture is burned, theporous insulation P or I4--I5 serving as a backfire trap to keep theheat of the flame from igniting the gas in the mixing chambers M, M2.The upper end of the porous insulation P or I4-I5 forms the bottom ofthe insulated primary combustion chamber C, in which chamber additionalair from ducts 5b r is fed to the burning gas-air mixture. Thisadditional air mixes with the original products of combustion, andpasses with them upwardly through grate 7 upon which is placed the layer9 of carborundum, aggregates or similar noncombustible material which isheated by the products of combustion to a high degree.

The layer 9 of combustible material serves the purpose of providing afine, even, odorless, flameless or almost flameless heat, and the excessair and products of combustion containing carbon passing through'theheated layer are combined to burn any residual carbon monoxide intocarbon dioxide, thus obtaining more heat from the fuel and eliminatingcarbon monoxide which is an active poison. This heat given off by thethe primary combustion can be absorbed therein as is the case when usingthe ordinary Bunsentype burner; also any fat, etc., dripping from thematerial being broiled will drop onto the heated layer 9 and will therebe burned without reach- 00 ing the primary combustion chamber C.

The actual combustion takes place in a substantially closed compartment(save for the secondary air inlets 5b which are protected from drafts)so that there is no danger that sudden air currents can extinguish theflame. Any gas leakage caused by accidental turning'on the gas cockswill not result in gas leaking into a room as any such gas passing mustpass into the combustion chamber C where it will be ignited by the pilotlight. Any grease falling on layer 9 during broiling cannot clog theburner, as it will be consumed directly on the heated and glowing layer.

Thus my burner provides an even, flowing, in-

15 tense heat, eliminating danger from carbon excess pressures in'theotherwise closed chamber,

and these inlets 5b are pointed down away fromany persons or anycombustible material which might be in the path of any gas flash.

' The burner will operate-regardless of the position in which it isplaced, whether vertical, horizontal or otherwise, since the poroussections serve to thoroughly distribute the gases passing through to theprimary combustion chamber, irrespective of the angularity of the axisof the burner; and the same flameless refractory bed appears at thesurface of the aggregates regardless of the position of the burner.

.Bumer units as above described may be used in place of the customaryburners in any types of gas cooking or heating stoves-or boilers.

I claim: v

1 A gas burner having a mixing chamber at one end and having itsopposite end open; means for introducing gas and air into said chamber;non-combustible porous packing in the open end of said burner throughwhich the gas-air mixture diffuses; an insulated casing forming aprimary combustion chamber into which the open end of the burnerprojects; means for admitting secondary air into the combustion chamber;said casing also forming a secondary combustion chamber adjacent saidprimary chamber; and a.

porous relatively thick layer of non-combustible material separatingsaid primary and secondary combustion chambers and adapted to be heatedto a high degree by the products of combustion.

2. In a gas burner as set forth in claim 1, a preformed cartridge-likeunit containing said packing; said unit substantially conforming withthe size and shape of said burner and filling the upper portion thereofand being insertable and removable therefrom through said open end.

3."In a gas burner'as set forth in claim 1, a preformed cartridge-likeunit containing said packing insertable and removable therefrom throughsaid open end; said unit comprising a shell conforming with the lengthand shape of said burner and filling the upper portion thereof and beingopen at both ends, a screen extending across said shell and spaced fromone end, a second screen across the other end, and said packing-beingdisposed between said screens.

4. In a gas burner as set forth in claim 1, a

conical cover over the porous packing, said cover having concentricseries of stepped portions provided with openings between the steps soas to divert liquids from passing therethrough while permitting thegas-air mixture to enter the primary combustion chamber therethrough.

5. In a gas burner as set forth in claim 1, a cover over the porouspacking of said mixing 1 chamber adapted to divert liquids therefromwhile permitting the gas-air mixture to enter the primary combustionchamber; said cover comprising a superimposed series of conical rings ofprogressively decreasing diameters, the overlapping faces of adjacentdisks being spaced apart.

6. In a gas burner as set forth in claim 1, a cover over the porouspacking of. said mixing chamber adapted to divert liquids therefromwhile permitting the gas-air mixture to enter the primary combustionchamber; said cover comprising a conical-shaped cap having. series oflouvres formed therein.

7. A gas burner having a mixing chamber;.

combustion chamber adjacent said primary combustion chamber; and aporous relatively thick layer of non-combustible material separatingsaid primary and secondary combustion chambers and adapted to be heatedto a high degree by the products-of combustion.

8. In a gas burner as set forth in-claim 7, a

preformed unit containing said packing for said secondary mixingchamber; said unit substantialy conforming with the size and shape ofsaid chamber and filling the upper portion thereof and being insertableand removable therefrom through .said open end; and said unit comprisinga shell open at both ends, a screen extending across said shell andspaced from one' end, a second screen across the other end, and saidpacking being disposed between said screens.

9. For a gas burner having a mixing chamber having side walls and openat.its upper end; the lower end being closed-and provided with an inletfor-introducing gas and air into said chamber; a preformed unit confinedwithin said chamber containing non-combustible porous packing, andsubstantially conforming with the area and shape of said mixing chamberand filling the upper portion thereof, said unit being insertable andremovable therefrom through said open end; a casing forming a primarycombustion chamber into which the open'end of the mixing chamberprojects; a secondary combustion chamber adjacent said primary chamber;and a porous relatively thick layer of non-combustible materialseparating said primary and secondary combustion chambers and adapted tobe heated to a high degree by the products of combustion. I

10. In a gas burner as set forth in claim 9, said unit comprising ashell open at both ends, a screen extending across said shell and spacedfrom one end, a second screen across the other end, and said porouspacking being disposed between said screens.

11. In a gas burner, a gas-air mixing chamber open at its upper end;said chamber having side walls and a bottom wall provided with a gas-airmixture inlet, a non-combustible porous packing .in said chamber abovethe bottom wall through 12. In a gas burner as set forth in claim 11,

said cover comprising a superimposed series of conical rings ofprogressively decreasing diameters, the overlapping faces of adjacentdisks be ingspaced apart.

13. In a gas burner as set forth in claim 11, said cover comprising aconical-shaped cap having series ofalouvres formed therein.

14. In a gas burner as set forth in claim 1i,.a

15. In a gas burner as set forth in claim 11, a

pre-formed unit containing said packing for said mixing chamber,insertable and removable therefrom through said open end; said unitcomprising a shell conforming with the length and shape of said mixingchamber and being open at both ends, a screen extending across saidshell and spaced from one end, a second screen across the other end, andsaid packing being disposed between said screens.

HENRY LOWE BROWNBACK.

